Manitowoc National Crane 800D - Page 223

National Crane Published 5-27-2018 Control # 039-06 10-7
800D CRANE INSTALLATION
4. Two methods of counterweighting may be used: (A) a
heavy front bumper and concrete in the bed or (B)
concrete in the bed only. The easiest and most
economical method is usually concrete in bed only. The
amount of counterweight required will be 566 + 428 =
994 lb (258 + 195 = 453 kg). Use 1150 lb (520 kg) of
concrete poured in the front of the bed. See
“Counterweighting for 180° Stability” in this section.
5. Determine axle weights added by the counterweight by
using the same method as used before. Figure the
center of the counterweight to determine where the
weight acts. If the counterweight is oddly shaped, figure
the center and weight of each regular shape. Weights
ahead of the front axle require using a negative (-)
distance in calculations.
The rear axle weight is 130 lb (57 kg) heavier than
required and the front axle weight is 26 lb (10 kg) heavier
than required.
6. Check the final weight of the unit with crane installed.
See “Specifications Section” for weight of 8100D and
center of gravity. Note that this weight does not include
weight of RSOD stabilizers [1300 pounds (590 kg)]-
REAR Front
=
Rear Axle Weight Front Axle Weight
1. Initial front axle wt. = 0 lb
= 0 kg 8000 - 0 = 8000 lb 3628 - 0 = 3628 kg
2. Pump & PTO’s = 34 lb
= 15 kg 150 - 34 = 116 lb 68 - 15 = 53 kg
3. Initial rear axle wt. = 7000 lb
= 3175 kg 7000 - 7000 = 0 lb 3175 - 3175 = 0 kg
4. Bed wt. = 1500 lb
= 680 kg 1456 - 1500 = – 44 lb 660 - 680 = – 20 kg
5. Add front and rear axle
wts. 8534 lb
3870 kg 8072 lb 3661 kg
6. Compare with wt.
required for this type of
mount from “Mounting
Configuration I” 9100 lb
4128 kg 8500 lb 3856 kg
Difference 566 lb
258 kg 428 lb 195 kg
(Weight) × (Distance From Front Axle)
Wheel Base
------------------------------------------------------------------------------------------------------
Rear Axle
Weight
Weight
Rear Axle
Weight
=
Front Axle
Weight
–
(8000) × 0
261
----------------------------
(3628) × 0
6629
----------------------------
(150) × 60
261
----------------------------
(68) × 1524
6629
-------------------------------
(7000) × 261
261
-----------------------------------
(3175) × 6629
6629
--------------------------------------
(1456) × 269
261
-----------------------------------
(660) × 6832
6629
-----------------------------------
(1752 mm)
69 in
(1752 mm)
69 in
(51 cm)
20 in
261 in
(6629 mm)
158 in
(4013 mm)
1150 lb
(520 kg)
CONCRETE
0 in
9450
Rear Axle Weight Front Axle Weight
1150 lb
(520 kg)
= 696 lb (1150) - 696 = 454 lb
Bed
Concrete
= 315 kg (520) - 315 = 205 kg
Required 566 lb 428 lb
Counterweight
258 kg 195 kg
Weights
130 lb 26 lb
Difference
(57 kg) (10 kg)
(1150) × 158
261
----------------------------------
(520) × 4013
6629
----------------------------------
Fo
r
Reference
Only